1. Field of the Invention
The invention relates to a battery pack capable of replacing a plurality of primary or secondary batteries, and more particularly to a battery pack which is easy-to-use and remarkably safe.
2. Description of the Background Art
Most of the currently prevailing portable electronic devices, including portable audio players of various kinds, PDAs (personal digital assistance) as typified by electronic notepads, and portable electronic games, use primary batteries, such as manganese batteries, alkaline batteries, or secondary batteries, such as nickel-cadmium batteries, as their power source. Such portable electronic apparatuses are generally designed to house a plurality of such batteries in a battery case and obtain necessary voltage therefrom.
FIG. 9 shows an example of such conventional art, wherein a battery case 41 is provided on the rear side of a portable electronic game to house 1.5V size AA batteries 42 and 43 and obtain 3V operating voltage therefrom. The battery case 41 comprises storage structures 44 and 45 separated by partition 46 to house batteries 42 and 43, respectively. A terminal board 47 positioned by the side of the positive terminal of the battery 42 comprises a positive battery terminal 48 in the shape of a ridging swell which is in contact with the positive terminal of battery 42. On the other hand, a terminal board 50 positioned by the side of the negative terminal of the battery 42 comprises a negative battery terminal 49 in the shape of a spring which is in contact with the negative terminal of the battery 42. Similarly, a positive battery terminal 51, and a negative battery terminal 52 which is connected to a terminal board 53 are positioned by the side of the positive and negative terminals of the battery 43, respectively, while the positive battery terminal 51 and the negative battery terminal 49 for the battery 42 commonly share the terminal board 50. In this structure, 2 size AA batteries are connected in series and 3V operating voltage is supplied to a positive input 54 and a negative input 55 of the power source of the electronic apparatus.
When the batteries 42 and 43 run out as a result of using the electronic apparatus, both batteries should be removed from the battery case and replaced with 2 unused batteries. In this case, those used batteries removed from the battery case easily get scattered and lost, causing inconvenience to users. In addition, when used batteries get scattered, they are often mixed up with unused batteries, which may result in erroneous loading of a used battery in a battery case with an unused one. Further, in the case of portable games, the users, especially children including those under school age, may not be able to insert batteries 42 and 43 in a battery case in the right direction. Such co-use of used and unused batteries, or insertion of batteries in the wrong direction not only causes failures in the electronic apparatus, but also endangers the safety of its users.
Moreover, when a positive terminal and a negative terminal of the conventional battery are connected electrically by any means, the circuit becomes short-circuited. This problem of short circuits, which may be caused by inappropriate storage of batteries or any other factors, raises concerns in terms of safety.